Electric range



May 5, 1931. c. D. STARR 1,804,130

ELECTRIC RANGE Filed Nov. 14. lsza N .Nrr) A w 67 Il ff 7 @isl A6 27 AAAAnn Patented May 5, 1931 i UNITED STATES PATENT OFFICE OLARENCED. STARR,0F BARRDGTON, RHODE ISLAND, ASSIGNOR T0 BARSTOW STOVE GOIPANY, 0l'PROVIDENCE, RHODE ISLAND, A CORPORATION 0F RHODE ISLAND ELECTRIC RANGEApplication led November 14, 1928. Serial No. 819,859.'

My invention relates to electric heating apparatus, and particularly butnot exclusively to electric ranges and other electrical devices forheating cooking vessels.

The invention, which has among its ob- -jects the control of theelectric heater by laccompanying `drawing showing one example of theinvention, while the scope of the invention will be more particularlypointed out in the appended claims.

. In the drawing Fig. 1 .shows an elevation, with parts incross-section, of a fragment of an electric range with a cooking vesselin operative relation to the heater;

Fig. 2 is a somewhat diagrammatic section on the line 2-2 of Fig..1; and

Figs. 3, 4, 5 and 6 are schematic wiring diagrams showing the maincontrolling switch in diierent operative positions.

Referrin to the drawing, the range illustrated is o the commonconstruction which comprises a frame having a top 1, the lattersupporting anfelectric resistance heating element 3, said element, aswill be understood by those skilled in the art, commonly comprising adisk or the like of heat refractory material carrying wire coilresistors in grooves on its upper face. The particular form of theelectric resistance heating element does not form part of the presentinvention, and therefore will be described with only such particularityas is necessary to explain how it coacts with the present invention.

Referring particularly to Figs. 3, 4, 5 and 6, the electric heatingelement, as herein indicated, comprises the resistors 5 and 7 which maybe of different heat generating capacity, the resistor 5, for example,being of small heat generating capacity and the `resistor 7 of largeheat generating capacity. As indicated in Fig. 1, at the front of the`range is positioned a controlling switch 9 having a rotary operatingknob 11. As shown (Figs. 3 to 6) the switch 9 is of the 3 point typehaving the three operating c ontacts 13, 14 and 15. One side 17 of theline, say a house lightingv circuit, is connected to the switch contact15, while the other side 19 of this line is connected by a lead 21 tothe common mid-terminal 23 of the resistors 5` and 7. The other terminal25 of the resistor 7 is connected by a lead 26 to the switch contact 13,and the other terminal 27 of the resistor 5 is connected by a lead 28 tothe switch contact 14.y The switch 9, which may be of the snap type,comprises, as schematically indicated in Figs. 3 to 6, the contact plate29 which may be rotated by the knob 11 about an axis 31 into thedifferent positions shown by these figures. Fig. 3'is the olf positionin which no current iiows through the resistors 5 and 7.. In theposition of parts shown by Fig. 4 current iiows through the low capacityresistor 5 to generate the smallest temperature of which the heater iscapable. In

the position of parts shown by Fig. 5 the resistors 5 and 7 areconnected in parallel across the line, and in this position of parts theheater illustrated generates the highest temperature oit' which it iscapable. In thel position of parts shown by Figs. 6 only the highcapacity resistor 7 is connected into the line, and in this position ofparts the heater generates a temperature between the low temperaturegenerated when the parts are in the position shown by Fig. 4 and thehigh temperature generated when the parts are in the position shown byFig. 5.

As herein indicated, the cooking vessel is `in the form of a coiee pot33 havmg a handie 35 through which extends a downwardly directed tube37. As shown, the tube 37 opens into the coffee pot adjacent its topthrough a port 39, While the tube terminates at its lower end at a pointabove the bottom of the coffee pot. As will be obvious, when steam isgenerated in the cooking vessel, a jet ofA steam will dischargedownwardly from the lower end oi the tube 37, and to facilitate this thespout 41 of the pot is herein provided with a lid 43 hinged at 45 and soconstructed as to prevent escape of steam from the spout during normalboiling of the contents of the pot without inter- IUU fering. with thepouring of such contents through the s ut.

As shown, neath the top of thel range is a casting or the like 4 7 havina horizon.- tal bore 49 o en at one end an intersected by a vertica bore51. As shown, a short tube 53 is provided for extending the bore 51 toabove the top of the range, this tube being readily removable from thebore 51, and the latter being provided with a shoulder 55 fordetermining the extent of pro'ection of the tube thereinto. As willbe ovious, when steam'is generated in the pot 33 a jet of steam will passthrough the tube l37, tube 53, bore 5l, and bore-49 and discharge to theatmosphere through the open end 50 of the latter, while if the lid 57 ofthe pot is raised a current ofv air will enter -the open end 50 of thebore- 49 yand pass upwardly through the bore 51, tube 53, and tube 37. l

As herein illustrated, the bore 49 contains a thermostatic element 59which in ay be of any suitable type, but as herein lndlcated is a coiledbi-metallic strip ixedly supported at one end 61 to a switch casing 63,and at its opposite end 65 connected to a rotary shaft 67 which extendsinto this switch casing. As shown, the casing 63 closes one end of thebore 49 and supports or forms part of the casing of the controllingswitch '9.

As illustrated, the thermostatic element' 59 o erates a switch 69,schematically shown in igs. 3 to 6, this switch herein being placed inthe lead 26 which connects the terminal 25 of the high capacity resistor7 to the switch contact 13, so that o ening and closing of the switch69, with t e parts in the position shown by Figs. 5 and 6, will beeffective to establish or interrupt flow of current through the highcapacity resistor 7.

Herein that end of the shaft 67 which is within the casing 63 hasrotatably mount-- ed thereon an arm 71 of insulating material, the lowerend of said arm carrying a pair of pins 73 between which extends one endof a leaf spring 75, theopposite end of which is rigidly connected tothe end of the shaft 67. As shown, the arm 71 has interally formedtherewith a lateral projection 6 which pivotally supports at 77 a metalblock 78 cooperating with a pair of contacts 79, the latter mounted on ablock 81 of insulating material and having theterminals 82 to permit theswitch to be placed in the lead 26, as schematically indicated at 69 inFigs. 3 to 6. As shown, the upper end of the arm 71 is provided with arounded projection 83 cooperating with the downwardly projecting camsurface 85 formed by the reversely curved end of a leaf spring 87, thelatter secured at its opposite end to the peripheral wall of the casing63.

The position of parts shown by Fig. 2 is that which exists when thethermostat is.

.Any

cold. If under these conditions the pot-boils, and the thermostaticelement is heated,

latter will tend to uncoil and rotate the shaft 67 clockwise, as viewedin Fig. 2. This clockwise rotation will flex the spring 75, .and whenthe alfort exertedwby this spring on the arm 71 overcomes ltheresistance oered by the' spring 87 to clockwise rotation of the arm, therojection `83 will sna past the downward y-projecting cam l sur ace 85and cause the plate 78 to move out 4tion of parts/indicated by 5 and 6.

When the thermostatic switch 1s o and the thermostatic element cools andt us tends to coil up, the spring 75 will be put under suicient flexureto snap the arm 71 into the position of parts illustrated by Fig. 2.further counter-clockwise movement of the shaft 67, after thethermostatic switch is closed, will result only in lexure of the spring75, and the same is true of clockwise movement after the switch. isopened and the arm 71 is brought up against the stop'- 89. It will thusbe observed that the spring 75 not only acts to cause a snap action ofthe thermostatic switch, but pre` form of thermostat disclosed is onlyone example of numerous thermostats that may be employed, also that theresistance heating element may consist of various arrangements oresistors controlled by the main switch in any desired manner.Preferably,

however, the resistance heatin Velement is so constructed and,socontrolla Ab the main switch that operation' of the t ermostatic switchinto open position will permit suficient heat being generated tomaintain a low temperature conditio 4when the main controlling switch isin the position in which the heating element generates the maximum heat.It will also be understood that other deviations from the specificembodiment .of the invention herein disclosed may be made withoutdeparting from the spirit of the invention.,

I claim:

1. An electricy range for cooking vessels having, in combination, anelectric heating element, a frame carrying said heatingY element, avertically directed flue for connection to a cooking vessel,`s aid fluebeing carried by said frame and having open ends, a thermostatic switchfor controlling current flow through said heating element, said -elementin said iue, an

thermostatic switch having a heatI sensitive element in said ue.

2. An electric range` for vessels having, in combination an electricheating element, a frame ca said heating element,.a vertically directediue for connectionl to a cooking vessel said iue being carried by saidframe and having o n ends, a thermostatic switch for contro 'ng currentflow through said heating element, said thermostatic switch havin a heatsensitive connections between said thermostatic switch and said heatingelement for causing ascending air currents thro heatin ei'ect of saidheating element and deseen 'n steam currents to -decrease the heatingeect of said heating element.

3. An electric range for cooking vessels having, in combination, Aaframe, an electric heating element at the upper side of said frame, avertically directed iiue for connection to a cooking vessel, 'said flue-ha open ends and be' carried by said frame, the lower end of sai fluebein at the under side of said frame below sai heating element, athermostatic switch for controlling current flow through said heatingelement, said switch having a heat sensitive element in saidflue, andconnections between said switch and said heating element for causingascending air currents throu h saidiiue to increase the heatingeiiect osaid heating element and descendin steam currents to decrease theheating eect of said heating element. l'

4. An electric range for cooking veels having, in combination, a frame,an electric heating element carried bg said frame, a thermostatic switchcarrie by said frame .for controlling current flow through said heatingelement, said switch having a heat sensitive element at the under sideof said frame below said heating element, and av vertically directedopen-ended iue for connection to a cooking vessel, said ue carried ,bysaid frameand arranged to direct ascending air currents and descendcurrents against said heat sensitive e ement.

In testimony whereof, I have signed my name to this specification.

` CLARENCE D. STARR.

ugh said iiue to increase the' steam Y

